Python QgsGeometry.pointOnSurface方法代码示例

# 需要导入模块: from qgis.core import QgsGeometry [as 别名]
# 或者: from qgis.core.QgsGeometry import pointOnSurface [as 别名]
    def processAlgorithm(self, progress):
        layer = dataobjects.getObjectFromUri(
            self.getParameterValue(self.INPUT_LAYER))

        writer = self.getOutputFromName(
            self.OUTPUT_LAYER).getVectorWriter(
                layer.fields().toList(),
                QGis.WKBPoint,
                layer.crs())

        features = vector.features(layer)
        total = 100.0 / len(features)

        for current, input_feature in enumerate(features):
            output_feature = input_feature
            if input_feature.constGeometry():
                input_geometry = QgsGeometry(input_feature.geometry())
                output_geometry = input_geometry.pointOnSurface()
                if not output_geometry:
                    raise GeoAlgorithmExecutionException(
                        self.tr('Error calculating point on surface'))

                output_feature.setGeometry(output_geometry)

            writer.addFeature(output_feature)
            progress.setPercentage(int(current * total))

        del writer

# 需要导入模块: from qgis.core import QgsGeometry [as 别名]
# 或者: from qgis.core.QgsGeometry import pointOnSurface [as 别名]
    def in_mask(self, feature, srid=None):
        if feature is None:  # expression overview
            return False

        if self.layer is None:
            return False

        try:
            # layer is not None but destroyed ?
            self.layer.id()
        except:
            self.reset_mask_layer()
            return False

        # mask layer empty due to unloaded memlayersaver plugin > no filtering
        if self.layer.featureCount() == 0:
            return True

        mask_geom, bbox = self.mask_geometry()
        geom = QgsGeometry(feature.geometry())
        if not geom.isGeosValid():
            geom = geom.buffer(0.0, 1)

        if geom is None:
            return False

        if srid is not None and self.layer.crs().postgisSrid() != srid:
            src_crs = QgsCoordinateReferenceSystem(srid)
            dest_crs = self.layer.crs()
            xform = QgsCoordinateTransform(src_crs, dest_crs, QgsProject.instance())
            try:
                geom.transform(xform)
            except:
                # transformation error. Check layer projection.
                pass

        if geom.type() == QgsWkbTypes.PolygonGeometry:
            if self.parameters.polygon_mask_method == 2 and not self.has_point_on_surface:
                self.parameters.polygon_mask_method = 1

            if self.parameters.polygon_mask_method == 0:
                # this method can only work when no geometry simplification is involved
                return (mask_geom.overlaps(geom) or mask_geom.contains(geom))
            elif self.parameters.polygon_mask_method == 1:
                # the fastest method, but with possible inaccuracies
                pt = geom.vertexAt(0)
                return bbox.contains(QgsPointXY(pt)) and mask_geom.contains(geom.centroid())
            elif self.parameters.polygon_mask_method == 2:
                # will always work
                pt = geom.vertexAt(0)
                return bbox.contains(QgsPointXY(pt)) and mask_geom.contains(geom.pointOnSurface())
            else:
                return False
        elif geom.type() == QgsWkbTypes.LineGeometry:
            if self.parameters.line_mask_method == 0:
                return mask_geom.intersects(geom)
            elif self.parameters.line_mask_method == 1:
                return mask_geom.contains(geom)
            else:
                return False
        elif geom.type() == QgsWkbTypes.PointGeometry:
            return mask_geom.intersects(geom)
        else:
            return False